The present invention relates to an adjustable, mountable Doppler ultrasound transducer device, especially to facilitate the continuous monitoring of blood flow velocity in human subjects.
Doppler ultrasound is commonly used for the non-invasive detection of fluid flow in human vessels, and for the diagnosis of blood flow disorders in all parts of the body. For example, during certain Doppler ultrasound procedures it is desirable to continuously monitor blood flow signals from a patient for extended periods of time. One such procedure is during the evaluation of the basil cerebral arteries with transcranial Doppler (TCD) ultrasound (Ringlestein, E.B., Transcranial Doppler Monitoring, chapter 10 in Transcranial Doppler Sonography, Aaslid, R. editor, Springer-Verlag 1986.). TCD, which was first described by Aaslid in 1982 (Aasilid, R., Markwalder, T., Nornes, H., Non-Invasive Transcranial Doppler Ultrasound Recording of Flow Velocity of Basal Cerebral Arteries, J. Neurosurgery, 57:1982, 769-774.), uses low frequency ultrasound directed through the intact cranium to detect and display the blood flow velocity and hemodynamics of the circle of Willis and its branches. Recent experience with TCD indicates a need for continuous monitoring of the cerebral circulation during certain surgical procedures that interrupt the normal hemodynamics of the circle of Willis. Carotid endartorectomy and heart valve replacement surgery are examples of surgical procedures where continuous TCD monitoring is useful.
Continuous monitoring is also helpful, for example, in numerous preoperative as well as postoperative situations, as well as in intensive care arenas, and anywhere else where a patients condition should be constantly monitored.
In an attempt to meet this need, U.S. Pat. No. 4,556,066, Semrow, discloses an ultrasound acoustical coupling pad that is secured to a patient's body and that retains a transducer. However, there is still a need for a simple and economical mountable Doppler ultrasound transducer device that can be steered, i.e. where the position of the transducer proper can be varied relative to the body of a patient.
It is therefore an object of the present invention to provide a relatively small, lightweight, and inexpensive mountable Doppler ultrasound transducer device, the position of which relative to the body can be altered in a rapid and straightforward manner.